1. Field of the Invention
The present invention is directed to a cranial orthosis to treat abnormal head shape in infants such as positional and/or deformational plagiocephaly and more particularly for providing a cranial orthosis with a safety feature and a method of application.
2. Description of Prior Art
Abnormal head shape in infants can result from a number of factors including inutero constraint, torticollis, sleeping position or any combination of these influences. In recent years, a documented increase in deformational plagiocephaly has been observed as a result of a change in the recommended sleeping position of the child to a supine sleeping position in an effort to reduce the risk of Sudden Infant Death Syndrome (SIDS).
The options available for the treatment of deformational plagiocephaly can include cranial vault remodeling surgery wherein the bones of the infant""s calvarium are removed under general anesthesia, reshaped and replaced. This surgical procedure obviously encompasses all the risks commonly associated with major surgery. Specialists in this field including pediatricians, craniofacial surgeons and pediatric neurosurgeons have generally recognized that deformational plagiocephaly is a result of an extrinsic molding force and that surgery should only be resorted to as the last alternative. The preferred treatment option is orthotic cranioplasty in which a corrective orthosis is custom made for each patient. These orthoses apply mild pressure to the protruding areas of the deformity and leave room for growth in those areas that were flattened during the original deformation. The pressure applied should be limited to prevent skin breakdown or other harm to the infant. The effect of this orthotic cranioplasty in treating deformational plagiocephaly has been documented in the Journal of pediatrics, January 1979, page 499 in an article entitled, xe2x80x9cHelmet Treatment for Plagiocephaly and Congenital Muscular Torticollisxe2x80x9d by Clarren, et al. Reference can also be made to a subsequent U.S. Pat. No. 4,776,324 by one of the authors.
Generally, the treatment period can average 4 to 5 months and may even require a series of cranial orthoses to provide the desired shape. During this time period, the infant patient is basically being administered by his/her primary care provider, e.g., parent or parents that are not trained orthotists. The cranial orthosis is frequently removed and re-applied during this time period and the infant patient can not provide comment on any excessive application of pressure by the cranial orthosis.
There is still a desire in the orthopaedic industry to provide improvements and safety features in cranial orthosis.
A cranial orthosis includes a corrective head contact member mounted for example in a helmet member for mounting on a patient""s head. The helmet member is configured for adjustment to permit an initial mounting and a subsequent application of confining pressure against selective areas of the head and voids to permit corrective growth. An interior surface of the helmet has been configured to provide a desired post treatment shape for the patient""s head and a safety stop unit is positioned on the helmet member to provide a safety limit to any application of excessive pressure against the patient""s head. The helmet member can be open on top or can extend about the entire patient""s head or at least about the treatment area with a flexible member forming a portion of the helmet member. A strap member can be used for biasing the helmet member to an operative position to provide the desired treatment to the patient""s head with the strap member anchored to the helmet member so that it can be tightened to maintain an operative position of the helmet member. An outer shell of the helmet member can be further split vertically along one side from top to bottom and a stop unit can be positioned to limit any closing movement of the edges of the helmet member on either side of the split opening. The stop unit can be formed as a bellows or diaphragm that can expand and contract and when contracted provides a stop position against any further closure of the helmet member on the patient""s head. Other forms of the stop unit can be provided, such as a series of non-compressible spacers that are aligned on a resilient flexible band to limit contraction of the helmet while permitting expansion for insertion on the patient""s head. Additionally, a stop unit can be positioned on a flange with a flexible resilient member positioned at a location inward from the stop unit. The stop unit may be positioned to define a secure contraction position of the helmet member to provide a positive alignment position for an untrained care provider.
The method of the present invention includes expanding the cranial orthosis for insertion about the treatment area of the patient""s head and contracting the cranial orthosis to secure it on the patient""s head within the limits of a safety stop member position.